| 摘要 |
PURPOSE:To reduce the size of a comb line type band-pass filter (BPF) for microwaves even when a load is high by interposing aperture type coupling windows among resonators constituting the comb line type BPF. CONSTITUTION:The electric axial length of resonating elements 41-4n made of bar conductors is set to a quarter resonance length lambda when the width H of a housing 1 and the diameters of the resonating elements are relatively less (e.g. 0.1lambda and 0.2lambda) than the resonance wavelength lambda, and the electric axial length of the resonating element is made adequately less than a quarter the resonance wavelength; and ungrounded end parts of the resonating elements are held in electrically open or nearly open states. Then, aperture type coupling windows 51-5n-1 have upper, external, and lower edges in contact with intermediate parts of adjacent resonating elements, e.g. the upper wall, side wall, and bottom wall of the housing 1 corresponding to a half the center-axis interval while set parallel to the axial direction of the resonating elements, and also arranged at the facing interval between two facing conductor plates 51' and 5n-1' perpendicular to the side wall of the housing 1. |
